Merge "Use FakeTimer in test to avoid flakiness."

src/com/android/settings/accessibility/ScreenFlashNotificationColorDialogFragment.java

@@ -119,7 +119,7 @@ public class ScreenFlashNotificationColorDialogFragment extends DialogFragment i
         synchronized (this) {
             if (mTimer != null) mTimer.cancel();
 
-            mTimer = new Timer();
+            mTimer = createTimer();
             if (mIsPreview) {
                 mTimer.schedule(getStopTask(), 0);
                 startDelay = BETWEEN_STOP_AND_START_DELAY_MS;
@@ -176,4 +176,8 @@ public class ScreenFlashNotificationColorDialogFragment extends DialogFragment i
         getContext().sendBroadcast(stopIntent);
         mIsPreview = false;
     }
+
+    Timer createTimer() {
+        return new Timer();
+    }
 }

tests/robotests/src/com/android/settings/accessibility/ScreenFlashNotificationColorDialogFragmentTest.java

@@ -42,6 +42,7 @@ import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.FragmentActivity;
 
 import com.android.settings.R;
+import com.android.settings.testutils.FakeTimer;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -49,9 +50,12 @@ import org.junit.runner.RunWith;
 import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.shadows.ShadowContextWrapper;
+import org.robolectric.util.ReflectionHelpers;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Timer;
+import java.util.function.Consumer;
 
 @RunWith(RobolectricTestRunner.class)
 public class ScreenFlashNotificationColorDialogFragmentTest {
@@ -68,9 +72,8 @@ public class ScreenFlashNotificationColorDialogFragmentTest {
         mShadowContextWrapper = shadowOf(fragmentActivity);
 
         mCurrentColor = ROSE.mColorInt;
-        mDialogFragment = ScreenFlashNotificationColorDialogFragment.getInstance(
+        mDialogFragment = createFragment();
-                mCurrentColor, selectedColor -> mCurrentColor = selectedColor
+
-        );
         mDialogFragment.show(fragmentActivity.getSupportFragmentManager(), "test");
 
         mAlertDialog = (AlertDialog) mDialogFragment.getDialog();
@@ -91,16 +94,19 @@ public class ScreenFlashNotificationColorDialogFragmentTest {
     }
 
     @Test
-    public void clickNeutral_assertStartPreview() throws InterruptedException {
+    public void clickNeutral_assertStartPreview() {
         performClickOnDialog(BUTTON_NEUTRAL);
-        Thread.sleep(100);
+        getTimerFromFragment().runOneTask();
 
-        Intent captured = getLastCapturedIntent();
+        assertStartPreview(ROSE.mColorInt);
-        assertThat(captured.getAction()).isEqualTo(ACTION_FLASH_NOTIFICATION_START_PREVIEW);
+    }
-        assertThat(captured.getIntExtra(EXTRA_FLASH_NOTIFICATION_PREVIEW_TYPE, TYPE_SHORT_PREVIEW))
+
-                .isEqualTo(TYPE_LONG_PREVIEW);
+    @Test
-        assertThat(captured.getIntExtra(EXTRA_FLASH_NOTIFICATION_PREVIEW_COLOR, Color.TRANSPARENT))
+    public void clickNeutral_flushAllScheduledTasks_assertStopPreview() {
-                .isEqualTo(ROSE.mColorInt);
+        performClickOnDialog(BUTTON_NEUTRAL);
+        getTimerFromFragment().runAllTasks();
+
+        assertStopPreview();
     }
 
     @Test
@@ -116,51 +122,47 @@ public class ScreenFlashNotificationColorDialogFragmentTest {
     }
 
     @Test
-    public void clickNeutralAndPause_assertStopPreview() throws InterruptedException {
+    public void clickNeutralAndPause_assertStopPreview() {
         performClickOnDialog(BUTTON_NEUTRAL);
-        Thread.sleep(100);
+        getTimerFromFragment().runOneTask();
         mDialogFragment.onPause();
-        Thread.sleep(100);
 
-        assertThat(getLastCapturedIntent().getAction())
+        assertStopPreview();
-                .isEqualTo(ACTION_FLASH_NOTIFICATION_STOP_PREVIEW);
     }
 
     @Test
-    public void clickNeutralAndClickNegative_assertStopPreview() throws InterruptedException {
+    public void clickNeutralAndClickNegative_assertStopPreview() {
         performClickOnDialog(BUTTON_NEUTRAL);
-        Thread.sleep(100);
+        getTimerFromFragment().runOneTask();
         performClickOnDialog(BUTTON_NEGATIVE);
-        Thread.sleep(100);
 
-        assertThat(getLastCapturedIntent().getAction())
+        assertStopPreview();
-                .isEqualTo(ACTION_FLASH_NOTIFICATION_STOP_PREVIEW);
     }
 
     @Test
-    public void clickNeutralAndClickPositive_assertStopPreview() throws InterruptedException {
+    public void clickNeutralAndClickPositive_assertStopPreview() {
         performClickOnDialog(BUTTON_NEUTRAL);
-        Thread.sleep(100);
+        getTimerFromFragment().runOneTask();
         performClickOnDialog(BUTTON_POSITIVE);
-        Thread.sleep(100);
 
-        assertThat(getLastCapturedIntent().getAction())
+        assertStopPreview();
-                .isEqualTo(ACTION_FLASH_NOTIFICATION_STOP_PREVIEW);
     }
 
     @Test
-    public void clickNeutralAndClickColor_assertStartPreview() throws InterruptedException {
+    public void clickNeutralAndClickColor_assertStartPreview() {
         performClickOnDialog(BUTTON_NEUTRAL);
-        Thread.sleep(100);
+        getTimerFromFragment().runOneTask();
         checkColorButton(CYAN);
-        Thread.sleep(500);
+        // When changing the color while the preview is running, the fragment will schedule three
+        // tasks: stop the current preview, start the new preview, stop the new preview
+        int numOfPendingTasks = getTimerFromFragment().numOfPendingTasks();
+        // Run all the pending tasks except the last one
+        while (numOfPendingTasks > 1) {
+            getTimerFromFragment().runOneTask();
+            numOfPendingTasks--;
+        }
 
-        Intent captured = getLastCapturedIntent();
+        assertStartPreview(CYAN.mColorInt);
-        assertThat(captured.getAction()).isEqualTo(ACTION_FLASH_NOTIFICATION_START_PREVIEW);
-        assertThat(captured.getIntExtra(EXTRA_FLASH_NOTIFICATION_PREVIEW_TYPE, TYPE_SHORT_PREVIEW))
-                .isEqualTo(TYPE_LONG_PREVIEW);
-        assertThat(captured.getIntExtra(EXTRA_FLASH_NOTIFICATION_PREVIEW_COLOR, Color.TRANSPARENT))
-                .isEqualTo(CYAN.mColorInt);
     }
 
     @Test
@@ -168,6 +170,7 @@ public class ScreenFlashNotificationColorDialogFragmentTest {
         checkColorButton(AZURE);
         performClickOnDialog(BUTTON_NEGATIVE);
 
+        assertThat(getTimerFromFragment()).isNull();
         assertThat(mCurrentColor).isEqualTo(ROSE.mColorInt);
     }
 
@@ -193,4 +196,46 @@ public class ScreenFlashNotificationColorDialogFragmentTest {
         final int size = capturedIntents.size();
         return capturedIntents.get(size - 1);
     }
+
+    private ScreenFlashNotificationColorDialogFragment createFragment() {
+        ScreenFlashNotificationColorDialogFragmentWithFakeTimer fragment =
+                new ScreenFlashNotificationColorDialogFragmentWithFakeTimer();
+        ReflectionHelpers.setField(fragment, "mCurrentColor", mCurrentColor);
+        ReflectionHelpers.setField(fragment, "mConsumer",
+                (Consumer<Integer>) selectedColor -> mCurrentColor = selectedColor);
+
+        return fragment;
+    }
+
+    private FakeTimer getTimerFromFragment() {
+        return (FakeTimer) ReflectionHelpers.getField(mDialogFragment, "mTimer");
+    }
+
+    private void assertStartPreview(int color) {
+        Intent captured = getLastCapturedIntent();
+        assertThat(captured.getAction()).isEqualTo(ACTION_FLASH_NOTIFICATION_START_PREVIEW);
+        assertThat(captured.getIntExtra(EXTRA_FLASH_NOTIFICATION_PREVIEW_TYPE, TYPE_SHORT_PREVIEW))
+                .isEqualTo(TYPE_LONG_PREVIEW);
+        assertThat(captured.getIntExtra(EXTRA_FLASH_NOTIFICATION_PREVIEW_COLOR, Color.TRANSPARENT))
+                .isEqualTo(color);
+    }
+
+    private void assertStopPreview() {
+        assertThat(getTimerFromFragment().numOfPendingTasks()).isEqualTo(0);
+        assertThat(getLastCapturedIntent().getAction())
+                .isEqualTo(ACTION_FLASH_NOTIFICATION_STOP_PREVIEW);
+    }
+
+    /**
+     * A {@link ScreenFlashNotificationColorDialogFragment} that uses a fake timer so that it won't
+     * create unmanageable timer threads during test.
+     */
+    public static class ScreenFlashNotificationColorDialogFragmentWithFakeTimer extends
+            ScreenFlashNotificationColorDialogFragment {
+
+        @Override
+        Timer createTimer() {
+            return new FakeTimer();
+        }
+    }
 }

tests/robotests/src/com/android/settings/testutils/FakeTimer.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.testutils;
+
+import java.util.PriorityQueue;
+import java.util.Timer;
+import java.util.TimerTask;
+
+/**
+ * A fake {@link Timer} that doesn't create a TimerThread which is hard to manage in test.
+ */
+public class FakeTimer extends Timer {
+    private final PriorityQueue<ScheduledTimerTask> mQueue = new PriorityQueue<>();
+
+    public FakeTimer() {
+    }
+
+    @Override
+    public void cancel() {
+        mQueue.clear();
+    }
+
+    @Override
+    public void schedule(TimerTask task, long delay) {
+        mQueue.offer(new ScheduledTimerTask(System.currentTimeMillis() + delay, task));
+    }
+
+    /**
+     * Runs the first task in the queue if there's any.
+     */
+    public void runOneTask() {
+        if (mQueue.size() > 0) {
+            mQueue.poll().mTask.run();
+        }
+    }
+
+    /**
+     * Runs all the queued tasks in order.
+     */
+    public void runAllTasks() {
+        while (mQueue.size() > 0) {
+            mQueue.poll().mTask.run();
+        }
+    }
+
+    /**
+     * Returns number of pending tasks in the timer
+     */
+    public int numOfPendingTasks() {
+        return mQueue.size();
+    }
+
+    private static class ScheduledTimerTask implements Comparable<ScheduledTimerTask> {
+        final long mTimeToRunInMillisSeconds;
+        final TimerTask mTask;
+
+        ScheduledTimerTask(long timeToRunInMilliSeconds, TimerTask task) {
+            this.mTimeToRunInMillisSeconds = timeToRunInMilliSeconds;
+            this.mTask = task;
+        }
+
+        @Override
+        public int compareTo(ScheduledTimerTask other) {
+            return Long.compare(this.mTimeToRunInMillisSeconds, other.mTimeToRunInMillisSeconds);
+        }
+    }
+}